Cosgrove was born near Alexandria Bay, New York in Jefferson County, New York. He attended schools in Redwood, New York, studied law in Watertown, New York and was admitted to the bar in 1863. He moved to Boonville, Missouri in 1865 and was Boonville city attorney 1870-1871 and was elected prosecuting attorney of Cooper County, Missouri in 1872; delegate to the Democratic National Conventions in 1872 and 1920; again city attorney of Boonville from April 1877 to April 1878 and from April 1879 to April 1881; elected as a Democrat to the Forty-eighth Congress (March 4, 1883 - March 3, 1885); was renominated in 1884, but withdrew before election day; resumed the practice of law in Boonville, Mo., where he died August 15, 1925; interment in Walnut Grove Cemetery.
|United States House of Representatives|
Ira Sherwin Hazeltine
|Member of the U.S. House of Representatives
from Missouri's 6th congressional district
John T. Heard